Yamaha Big Bear 2x4 YFM350UH Service Manual, 1996–1999 (P/N LIT-11616-10-08, 4UH-28197-20)

Yamaha service manual for the YFM350UH Big Bear 2x4, with regional specification tables headed YFM350U. This is the first edition, August 1995, identified by P/N LIT-11616-10-08 and 4UH-28197-20.

PDF Search, Diagram Detail, and Page Count

Search and navigation: PDF text search and embedded bookmarks are not available. Small wire codes and connector labels in the electrical diagrams require zooming.

The ZIP download contains one printable, English-language PDF with 315 pages, including the original covers and front matter.

Engine Overhaul, Shaft-Drive Repair, and Circuit Diagnosis

These selected service topics outline the repair coverage rather than reproduce the complete contents. Additional subjects include battery inspection and headlight-beam adjustment.

• Engine repair: Engine removal and remounting, cylinder-head and piston work, crankcase separation, crankshaft and balancer inspection, oil-pump service, and clutch/transmission reassembly.

• Carburetion: Mikuni BTM32SH carburetor removal, disassembly, inspection, assembly, installation, and fuel-level adjustment.

• Periodic inspection: Valve-clearance, idle, throttle, speed-limiter, ignition-timing and compression checks, clutch adjustment, air-filter service, oil changes, toe-in, and shock settings.

• Drivetrain repair: Middle drive and driven gears, damper and universal-joint service, shim selection, gear-lash adjustment, and rear-axle, final-drive and drive-shaft repair.

• Brakes and chassis: Hydraulic front drum-brake overhaul and bleeding, rear drum-brake repair, wheel service, steering-shaft and tie-rod work, front arms, shocks, and swingarm inspection.

• Electrical diagnosis: Ignition, electric-starting, charging, lighting, and signal-system circuit diagrams, component tests, starter-motor overhaul, and step-by-step fault-tracing charts.

Written primarily for Yamaha dealers and qualified mechanics, this manual assumes a basic understanding of mechanical repair concepts and procedures.

Regional Specifications and Parts Identification

The regional codes and starting numbers help match the publication to the machine before selecting regional parts or service data. Separate cable-routing drawings cover USA/Canada/Europe and Australia.

Carburetor identification marks are 3HN 00 for USA/Canada/Europe and 4UM 00 for Australia. Regional tables also distinguish dimensions, spark-plug applications, idle settings, headlamp and indicator-bulb ratings, and horn equipment.

Engine Inspection and Workshop References

The overhaul chapter provides step-by-step procedures for camshaft, rocker-arm and valve work, including valve-guide replacement and valve-seat inspection and lapping. Piston-ring inspection, timing-chain and CDI-rotor service, and recoil-starter repair are also covered.

Engine-removal notes identify cylinder-head, cylinder, piston, clutch and CDI-rotor work that does not require removing the complete engine. This distinction supports planning the extent of disassembly for the intended repair.

Exploded assembly views accompany the crankshaft, middle-drive-axle and transmission group, primary and secondary clutches, and valve gear. Lubrication diagrams illustrate the oil circuit; supporting tables supply component-specific torques, wear limits, clearances, lubrication points and capacities.

Engine tools: The special-tool section identifies the valve-adjusting tool YM-08035 / 90890-05260, flywheel puller YM-01404 / 90890-01404, and crankcase separating tool YU-01135-A / 90890-01135, with descriptions of their applications.

Final-Drive Setup and Hydraulic Front Brakes

Drive-train procedures go beyond component removal. They include middle-gear and final-drive pinion/ring-gear shim selection, ring-gear thrust-washer selection, stopper-clearance adjustment, and gear-lash measurement.

Relevant tools include the gear-lash measurement tool YM-01231 / 90890-01231 and final-drive-shaft bearing-retainer wrench YM-04050 / 90890-04050. Exploded views show the middle-gear damper, universal joint, rear axle and final-drive assemblies.

The front-brake section treats the master cylinder, wheel cylinders, pipes and hoses separately, with disassembly, seal inspection, reassembly and bleeding requirements. Rear drum-brake procedures cover shoes, the camshaft, wear indicator, and lever/pedal adjustment.

Starting Interlocks and Electrical Fault Tracing

The starting-circuit explanation connects the neutral and reverse switches, rear-brake switch, relays and starter motor. Its test charts help distinguish an interlock or wiring fault from a starter-motor problem before overhaul is considered.

Ignition diagnosis includes spark, coil-resistance and switch-continuity checks. Charging tests address the stator and rectifier/regulator; lighting and signal charts cover lamps, indicators, the horn and oil-temperature warning circuit.

Overall wiring diagram: The separately indexed YFM350U wiring diagram is not included in this PDF. The five system circuit diagrams are included.

Troubleshooting and Repair Cautions

The final chapter groups hard-starting causes under fuel, electrical and compression systems. It also addresses poor idle and higher-speed performance, drivetrain noise, hard shifting, gear jump-out, clutch slip or drag, overheating, poor braking, shock-absorber faults, unstable handling and lighting problems.

Repair cautions explain how spinning cleaned bearings with compressed air can damage their surfaces, while solvent can swell and distort internal front-brake seals. Shaft-drive troubleshooting warns that insufficient gear lash can destroy gear teeth and identifies abnormal whine after reassembly as a reason to stop riding immediately.

Engine, brake, steering and drivetrain repairs require a qualified technician equipped to follow the Yamaha procedures, warnings and inspection requirements.

Examples of Valve and Clutch Inspection Data

Cold valve-clearance specifications are 0.06–0.10 mm for the intake and 0.16–0.20 mm for the exhaust. The adjustment section accompanies these settings with timing-mark illustrations and the specified valve-adjusting tool.

For secondary-clutch inspection, friction-plate thickness is 2.94–3.06 mm, with a 2.8 mm wear limit. Separate checks address clutch-plate warpage and spring length.